John a



@einen 'taire @anni @time JOHN A. GAMPDELD'OF SOUTH BOSTON,MASSACHUSETTS, ASSIG'NOR TO HIMSELF AND DAvID SHARP, or SAME PLAGE.

Letters .Patent No. 73,950, dated February 4, 1868.

IMPROVED GAR-BRAKE.

TO ALL "PERSONS TO WHQM THESE PRESENTS MAYGOME:

Be it known that I, JOHN A. CAMPBELL, of South Boston, in the county ofSu'olk, and State of Massachusetts, have made a new and usefulImprovement in Railway-Carriag'es; and do hereby declare the same to befully described in the following specification, and represented in theaccompanying drawings, of whichi Figure 1 denotes a side elevation,

Figure 2 a transverse section, and

Figure 3 a longitudinal section of a railway-car truck and platform asprovided with my invention, the purpose of which is either to arrest orcheck the motion of the carriage or car while such car may be inmovement' on a railway-truck.-

The invention in question may be styled an'improved brake-mechanism.

In the drawings, A denotes the platform, B the truck-frame, and C thetransom-bolt by which they are connected. The said truck-frame issupported in the ordinary manner by two axles, D D', applied to boxes orbearings arranged in such frame. Each axle has two wheels, E E. Thereextends from the middle cross-bar a of the truck-frame a series ofsprings or brakes, I; b b b, there bengone of them to each wheel. Theyare arranged over and with respect to the treads or peripheries of thewheels, as exhibited in the drawings". Each of these springs has anIndia-rubber bearing or auxiliary spring, h, extending from it up to theplatform A.

Underneath and parallel to the cross-bar a is another such bar, '0,which supports another setv of spring-brakes,

d d d d, arranged between and with respect to thewheels, in manner asshown in the drawings.

The transom-bolt C hasv two male screws, e f, formed on it. One of themscrews into and througlrthe bar a, and the other screws into andthroughthe bar c, there being a nut or plate, g, fixed to each bar toreceive the screw. These screws are to be Iso made that, when thetransom-bolt is revolved in one direction, the two bars avc shall becaused to approach each other, and to move apart when the` transom-boltis revolved in the' opposite way.

A gear, z', on the transom-bolt has an endlessbelt or chain, 7c, goingaround it, and another such gear, l, fixed on a vertical shaft, in, dulysupported in bearings applied to the platform, and provided with ahand-wheel, n. By means of these devices, the transom-holt may berevolved,so as to-eause, byits screws, the two bars a c either toapproach toward or recede from each other.

In being revolved in one direction, thetransom-bolt will lowertheplatform A, ormore it toward the wheels, so as to cause the uppersprings or brakes to bear upon the wheels. At the same time, the lowersprings or brakes will boIdrawn up to the wheels. In this way, as eachYlower and each upper spring of' a wheel bears on opposite parts of thecircumference of the saidwheehthe strain of the trucks willbeborne bythe wheel, and not by the axle. The truck-frame will be able to turn onthe transombolt.

I d o not claim applying brakes to opposite parts of a wheel, so as torelieve the axle thereof from the strain of such brakes when they areborne against the periphery of the wheel, the pressure pf one brake onthe wheel tending to force its axle aside, being. counteracted by thepressure of the when-brake, acting in an opposite direction.

I claim as my invention- The combination as well as the arrangement ofthe two screws e f ofthe transom-bolt C with such bolt,

the bars a c, andthe two series of brakes, applied to such bars and thewheels, or to the same and the platform A, substantially as described. v

And, in combination therewith, Ivclaim .the hand-wheel shaft m, itsgear' Z, and chain or belt k, and thel gear c' on the transom-bolt C,the whole being arranged substantially in manner and so as to operate asdescribed.

` J. A. CAMPBELL.

Witnesses:

1%. H. EDDY,

SAMUEL N. PIPER.

